Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
252 PM EST Mon Feb 9 2026

Valid 00Z Tue Feb 10 2026 - 00Z Fri Feb 13 2026


...Sierra Nevada to the Central Rockies...
Days 1-3...

A mid-level low in the northeast Pacific just north of a 150kt jet
streak this evening will move southeastward then eastward into
NorCal tomorrow night. This will direct a modest plume of moisture
into the Sierra with snow levels initially around 7000ft then
dropping to around 6000ft. Snow could fall at >1"/hr tomorrow night
in the higher Sierra (>8000ft) then subside through Wednesday. WPC
probabilities for at least 8 inches of snow are >50% above 6000ft
or so with >18" likely (<80%) above 8000ft.

The system will continue eastward as the upper jet strengthens
over the Great Basin to central Rockies as the upper trough remains
positively-tilted. Moisture will continue to funnel from the sub-
tropics into the Four Corners region (>90th percentile) on
southwesterly flow. Snow levels will waver around 6000-7000ft with
modest amounts expected in an area that has seen very little snow
this season. WPC probabilities for at least 8 inches of snow are
>50% above 7000ft or so in UT and 8000ft in WY. Snow will linger
longest over the CO Rockies through Thursday as the moisture plume
stalls there as a result of a second shortwave trailing the lead
system, maintaining SW flow through the end of this period. WPC
probabilities for at least 8 inches of snow are >50% above 10,000ft
or so in CO.


...Northern Great Lakes and Northeast...
Days 1-3...

A progressive closed mid-level low will elongate and track from
the Northern Great Lakes to across New England mid-week,
translating into the Gulf of Maine on Wednesday. This upper feature
will be accompanied by an extended vorticity lobe on its south
side along the occlusion, helping to produce strong ascent through
height falls/PVA across the region. As this develops, pronounced
warm air advection (WAA) will develop to its south up and over a
surface warm front across the Mid-Atlantic. Lead WAA- drive
precipitation will arrive over northern NY/New England tomorrow
evening followed by the frontal passage. CAA will ensue with some
lake effect and upslope snow across the region Wednesday through
Thursday.

Quasi-zonal flow will limit precipitation duration, but CAM
guidance still indicates a window of >1"/hr rates (50-80% chance)
over the Adirondacks, northern and central VT/NH, and into
southwest Maine between 21Z Tue and 04Z Wed (from west to east)
ahead of the occlusion and as it translates into the Gulf of Maine.
Behind the front, NW flow will support widespread multi-banded
lake effect snow downwind of all Great Lakes (less from mostly all-
frozen Erie) that will be enhanced at times from trailing vort
maxes streaming in from the NW.

WPC probabilities for at least 4 inches of snow for the event are
>50% over southwestern NY, central NY into the Adirondacks/North
Country, northern VT/NH and across much of Maine except for far
northern areas (removed from the higher QPF). Some favored upslope
areas could see in excess of 8 inches of snow, especially over the
Tug Hill into the Green Mountains.

Finally, as the closed low moves into the Gulf of Maine, a new
surface low down the occlusion will deepen offshore in response.
While direct impacts from this surface low are not expected to be
significant, the guidance (e.g., NAMnest, CMCreg) is hinting at a
lingering inverted trough pivoting back across coastal Maine
Wednesday afternoon/evening. These inverted troughs can sometimes
lead to sneaky-heavy snowfall accumulations. WPC probabilities for
at least 8 inches of snow between Bangor and Eastport are 25-45%
right now, and may change pending more hi-res guidance.


Fracasso/Weiss